Auto gearbox - a question 35 years too late

[gencybay]

Titter if you will. I learnt to drive using manuals. So long ago my father used to encourage me to double de-clutch to reduce wear on the synchromesh.

I got my first auto some time in the 70s. Apart from having to curl my left leg round to avoid stamping on the brake coming up to roundabouts, I had no difficulties. Put in D, go forward, R, go backwards. Finish journey, P and that's it. Well, except for leaving in D at end of journey and having palpitations the next day when the bugger wouldn't start. I still do that from time to time, after emptying the ashtray!

Anyway, it occurred to me that I have never been taught, or read up, on how an auto box should properly be used. I'm aware that you shouldn't hang on the ?pawl? on inclines but that's it.

So, is there a proper way to use an auto box that will contribute to it having a longer life and make me a better driver/owner?

G~

 

[Datatek]

It's auto by name and auto by nature. No need to do anything IMO. However I do use the lever to force downshifts for engine braking, particularly useful on long steep descents, can also make fuel savings on the P38 diesel as with the torque convertor locked the overrun fuel shut off operates. I also force down shifts when towing uphill to stop it hunting between gears.
The first strategy probably increases gearbox wear, the second definately reduces it.

 

[Saint.V8]

As above...I also use the Manual side on steep declines/inclines....

If I am going to wait at a set of traffic lights for a while, I do knock it into Neutral, with foot on brake or Hand Brake if on the flat.

Also after a long or hard braking event that will heat the discs up and I am standing still at traffic lights, I do place into N, then off foot brake to allow the discs to cool naturally, as the pressure from the brake pads on a hot disc can cause them to warp.

I do try to avoid harsh acceleration (unless provoked by a tw@t in Euro Box revving at the lights!!) and also heavy braking - I do drive like a Grandad even though I am 34 I have to say....

 

[Grit Valve]

Maybe just a couple do not change gearbox from one direction to the opposite while moving , including putting the lever in park and finally no revving the bo..... Out of it whilst stationary and then engaging gear. But you knew that didn't you .

 

[Datatek]

Maybe just a couple do not change gearbox from one direction to the opposite while moving , including putting the lever in park and finally no revving the bo..... Out of it whilst stationary and then engaging gear. But you knew that didn't you .

I thought the ECU was smart enough to prevent the change happening, it's certainly smart enough to stop down shifts at excessive speed?

Best fun in my youth was a Ford van with a Yankee V8/3 speed auto coupled to a Jag rear end, floor cut away to accommodate wide tyres, hold it on the brakes at the lights and lift the revs to torque convertor stall point, slide foot off the brake peddle and leave 30 foot of tyre marks up the road. Used to **** off the Mini Cooper, TR4 types no end

 

[Grit Valve]

I thought the ECU was smart enough to prevent the change happening, it's certainly smart enough to stop down shifts at excessive speed?

Best fun in my youth was a Ford van with a Yankee V8/3 speed auto coupled to a Jag rear end, floor cut away to accommodate wide tyres, hold it on the brakes at the lights and lift the revs to torque convertor stall point, slide foot off the brake peddle and leave 30 foot of tyre marks up the road. Used to **** off the Mini Cooper, TR4 types no end

Ya that's why it bleeps at you lol what about park mechanisms is the ecu that smart ?

 

[gencybay]

Maybe just a couple do not change gearbox from one direction to the opposite while moving , including putting the lever in park and finally no revving the bo..... Out of it whilst stationary and then engaging gear. But you knew that didn't you .

I nearly did the first by accident a few days ago! Noticed I was in 3rd. Pressed lock whilst pushing forward into drive. Fortunately only went as far forward as neutral.

I'm not too old to learn though. I always used to rev before turning engine off. Old wives tale about charging boost I think. It seems this is totally wrong with a turbo and that they should be allowed to wind down gently for a few moments. Handbrake? Used to believe that button should be depressed - nasty noise? I don't know. Now been told that the ratchet is essential for self-adjustment.

Just goes to show that we are able to make errors with the best intentions.

G~

 

[Saint.V8]

Modern handbrakes have the adjustment in the ratchet mechanism, so unfortunatly in modern cars you have to click it up....but on the P38 you can continue you depress the button when raising the lever and releasing at the top as the adjustment is done on the brake drum on the rear driveshaft output from the transfer box.

 

[gencybay]

That will please my wife. She was taught to depress the button as I was and sneers at the sound of the ratchet.

I shan't tell her that I have a logical reason for reverting to my old method. I'll just let her think that she's won.

G~

 

[Saint.V8]

That will please my wife. She was taught to depress the button as I was and sneers at the sound of the ratchet.

I shan't tell her that I have a logical reason for reverting to my old method. I'll just let her think that she's won.

G~

Smart man....like the style!!

 

[Grit Valve]

As for the turbo I do wait after long hi speed motorway trolls.. What a bout park brake whilst moving surely damage there?

 

[jamesmartin]

hand brake cable is adjusted on lever end of cable park is a rod with a pawl at the end which is thrust into a castleated wheel held by 2 small screws ,easy to break if you try applying while moving

 

[Grit Valve]

hand brake cable is adjusted on lever end of cable park is a rod with a pawl at the end which is thrust into a castleated wheel held by 2 small screws ,easy to break if you try applying while moving

Thanks James that what I was getting at. Iv noticed I've even done it prior to not being fully stationary and you can felel the car doesn't like it.

 

[qwertz]

I am not any more sure that selecting "N" at traffic light is making any change for GB in P38.

I believe it uses ZF 4HP-22/24 gearbox and there was a service bulletin issued by BMW in 1991 # 24 01 91 (3196) which says "The problem is that after starting the engine, and selecting any gear, forward or reverse, the front clutch pack in the transmission is pressurized, and that pressure is not bled off when park or neutral are selected. "

Is this a concern for P38 owners I don't know. It would be good to know if the problem was addressed in later years of ZF 4HP-22/24 production.

 

[qwertz]

Google "Caveats about the ZF automatic transmission!" Service bulletin and more info.

 

[jamesmartin]

it was an issue years ago on some on some bmws etc but never heard of it been an issue on rr,you are better to select n if waiting

 

[Tarquin]

"you are better to select n if waiting"

Why not select park if waiting?

 

[Grit Valve]

"you are better to select n if waiting"

Why not select park if waiting?

One it is further travel more wear two you might just select reverse

 

[gencybay]

So it's not just me. They're so simple that we just use them without knowing how they should best be treated.

G~